This application relates generally to an apparatus for supporting a semi-trailer on a railcar and more particularly, to a retractable stanchion used for supporting a semi-trailer on a deck of a railcar.
At least some known trailer supports, also known as stanchions, are mounted on a railcar deck and are retractable to facilitate loading and/or transportation of various types of storage containers such as, but not limited to, large storage vessels and/or semi-trailers. At least some known retractable stanchions include an engagement portion that is used for moving the retractable stanchion from a horizontal retracted position to a vertical erected position. However, the structure, position, and/or manner in which the engagement portion of the known retractable stanchions is engaged can vary.
At least some known retractable stanchions include an engagement portion that is fixed with respect to an outer frame of the respective stanchion. Therefore, the fixed engagement portion is inhibited from rotation with respect to an outer stanchion frame during an upward movement of the retractable stanchion from a horizontal retracted position to a vertical erected position. Other known retractable stanchions include an engagement portion that is pivotally mounted with respect to an outer stanchion frame. Therefore, similar to the fixed engagement portion, the pivotally mounted engagement portion is also inhibited from rotation with respect to the outer stanchion frame during an upward movement of the retractable stanchion from a horizontal retracted position to a vertical erected position.
These known fixed or pivotally mounted engagement portions may be engaged by manually operated mechanisms and/or machine driven mechanisms to raise the retractable stanchions from a horizontal retracted position to a vertical erected position. For example, a known retractable stanchion may be mounted on a deck of a railcar. The mounted retractable stanchion may initially rest in a horizontal retracted position so that the stanchion will not interfere with a loading of a semi-trailer onto the deck. A tractor and an attached semi-trailer may then be driven up a sloped ramp to move the semi-trailer onto one of a plurality of adjacent railcar decks that may each include a retractable stanchion. Once a semi-trailer kingpin is in predefined loading position, the tractor uses a trailer hook to raise the retractable stanchion to a vertical erected position. The tractor may then transfer the semi-trailer from the tractor to the erected retractable stanchion.
If both the tractor and the semi-trailer are disposed on substantially planar surfaces that are horizontally aligned, then a tractor hook may more easily erect the known retractable stanchions having the conventional fixed or pivotally mounted engagement bar. However, if the tractor is provided on a surface, such as a sloped ramp, lower than a deck top surface in which the semi-trailer is provided, the known retractable stanchion cannot be raised by engaging the conventional fixed or mounted engagement bar because of a vertical displacement of the tractor created by the sloped ramp. Therefore, the vertical displacement between the lower ramp surface and the higher deck surface of the semi-trailer supporting railcar creates a mechanical disadvantage.